Improving ipv6rd performance

[Beherit]

My ISP hasn't yet implemented full native ipv6 for their customers. They do, however, provide an ipv6rd gateway.

The downside of using it, is that my speed drops from ~700 mbit down to ~120 mbit. I am guessing this has something to do with hardware acceleration not being supported on the router, as both CPU cores on my RT-AC87U go up to 100%.

Is there any way to improve this?

And a related question, what kind of speed can I expect if I'd upgrade to an RT-AX88U?

 

[L&LD]

As a guess? Full speed on the RT-AX88U.

If you need the IPv6 today, it would be a great upgrade (and even better if you can test and return if not enough improvement for you).